CD47 is a ubiquitous cell surface receptor that limits cell clearance by phagocytes that express its counter-receptor signal-regulatory protein-a and directly regulates T cell immunity by interacting with its inhibitory ligand thrombospondin-1. Murine natural killer (NK) cells express higher levels of CD47 than other lymphocytes, but the role of CD47 in regulating NK cell homeostasis and immune function remains unclear. Cd47-/- mice exhibited depletion of NK precursors in bone marrow, but antisense Cd47 knockdown or gene disruption resulted in a dose dependent accumulation of immature and mature NK cells in spleen. Cd47-/- mice were impaired in controlling chronic Clone-13 lymphocytic choriomeningitis virus (LCMV) infection, which was associated with depletion of splenic NK cells and loss of effector cytokine and interferon response gene expression in Cd47-/- NK cells. These data identify CD47 as a cell-intrinsic and systemic regulator of NK cell homeostasis and NK cell responses to viral infection. Overall design: Examining natural killer (NK) cell intrinsic role of CD47 during viral infection.
CD47 Expression in Natural Killer Cells Regulates Homeostasis and Modulates Immune Response to Lymphocytic Choriomeningitis Virus.
Specimen part, Subject
View SamplesA key question in developmental biology is how cells exchange positional information for proper patterning during organ development. In plant roots the radial tissue organization is highly conserved with a central vascular cylinder in which two water conducting cell types, protoxylem and metaxylem, are patterned centripetally. We show that this patterning occurs through crosstalk between the vascular cylinder and the surrounding endodermis mediated by cell-to-cell movement of a transcription factor in one direction and microRNAs in the other. SHORT ROOT, produced in the vascular cylinder, moves into the endodermis to activate SCARECROW. Together these transcription factors activate MIR165a and 166b. Endodermally produced miR165/6 then acts to degrade its target mRNAs encoding class III homeodomain-leucine zipper transcription factors in the endodermis and stele periphery. The resulting differential distribution of target mRNA in the vascular cylinder determines xylem cell types in a dosage dependent manner.
Cell signalling by microRNA165/6 directs gene dose-dependent root cell fate.
Age, Specimen part
View SamplesBackground: Acute myeloid leukemia (AML) is driven by somatic mutations and genomic rearrangements affecting >20 genes. Many of these are recent discoveries and how this molecular heterogeneity dictates AML pathophysiology and clinical outcome remains unclear. Methods: We sequenced 111 leukemia genes for driver mutations in 1540 AML patients with cytogenetic and clinical data. We modeled AMLs genomic structure, defining genetic interactions, patterns of temporal evolution and clinical correlations. Results: We identified 5,236 driver mutations involving 77 loci, including hotspot mutations in MYC. We found 1 driver mutation in 96% patients, and 2 in 85%. Gene mutations implicated in age related clonal hematopoiesis (DNMT3A, ASXL1, TET2) were the earliest in AML evolution, followed by highly specific and ordered patterns of co-mutation in chromatin, transcription and splicing regulators, NPM1 and signaling genes. The patterns of co-mutation compartmentalize AML into 12 discrete molecular classes, each presenting with distinct clinical manifestation. Amongst these, mutations in chromatin and spliceosome genes demarcate a molecularly heterogeneous subgroup enriched for older AML patients currently classified as intermediate risk and results in adverse prognosis. Two- and three-way genetic interactions often implicating rare genes/mutation-hotspots, markedly redefined clinical response and long-term curability, with the NPM1:DNMT3A:FLT3ITD genotype (6% patients) identifying poor prognosis disease, whereas within the same class NPM1:DNMT3A:NRASG12/13 (3%) associated with favorable outlooks. Conclusions: 79% of AML is molecularly classified in 12 genomic subgroups. These represent distinct molecular phylogenies, implicating complex genotypes. Delineation of higher-order genomic relationships, guide the development of personally tailored classification, prognostication and clinical protocols. Similar studies across cancer types are warranted.
Genomic Classification and Prognosis in Acute Myeloid Leukemia.
Specimen part, Disease
View SamplesRobles-Valero et al. report a tumor suppression role for the otherwise oncogenic Vav1 Rho GEF. This paradoxical action is mediated by the catalysis-independent buffering of Notch1 signaling in immature T cells.
A Paradoxical Tumor-Suppressor Role for the Rac1 Exchange Factor Vav1 in T Cell Acute Lymphoblastic Leukemia.
Specimen part, Treatment
View SamplesAscertain the effects of disease-causing gene mutations on the differentiation status of human nave CD4+ T cells in the setting of primary immunodeficiencies. Thus, do CD4+ T cells isolated according to a nave surface phenotype (ie CD4+CD45RA+CCR7+) from healthy donors exhibit a similar gene expression profile as phenotpyically-matched cells isolated from individuals with defined primary immunodeficiencies caused by specific monogenic mutations.
Unique and shared signaling pathways cooperate to regulate the differentiation of human CD4+ T cells into distinct effector subsets.
Specimen part
View SamplesAcute lymphoblastic leukaemia with early T-cell precursor immunophenotype (ETP ALL) is a highly aggressive subtype of ALL of unknown aetiology. To gain insights into the genetic basis of this disease, we performed whole genome sequencing of tumour and normal DNA of 12 children with ETP ALL. Analysis of structural and sequence variants in this discovery cohort, and mutation recurrence screening in a panel of 51 ETP and 43 non ETP ALL samples identified a high frequency of activating mutations in genes regulating cytokine receptor and Ras signalling, including IL7R, NRAS, KRAS, FLT3, BRAF, JAK1 and JAK3 in ETP ALL. Moreover, we identified multiple new targets of mutation in including GATA3, EP300, RUNX1, DNM2, ECT2L, HNRNPA1 and HNRNPR, as well as genes known to be mutated in T-ALL, including NOTCH1, PHF6, and WT1.. Five of 12 ETP ALL cases harboured novel chromosomal translocations, several of which accompanied complex multichromosomal rearrangements and resulted in the expression of chimeric in-frame fusion genes disrupting hematopoietic regulators, including ETV6-INO80D, NAP1L1-MLLT10 and RUNX1-EVX1. These results indicate that although ETP ALL is genetically heterogeneous, activation of Ras and cytokine receptor signalling distinguishes this disease from non-ETP ALL. These findings suggest that targeting this pathway may improve the currently dismal outcome of this disease.
The genetic basis of early T-cell precursor acute lymphoblastic leukaemia.
Specimen part
View SamplesEarly T-cell precursor acute lymphoblastic leukaemia (ETP ALL) is an aggressive malignancy of unknown genetic basis. We performed whole genome sequencing of tumour and normal DNA from 12 children with ETP ALL and assessed the frequency of somatic alterations in 52 ETP and 42 non-ETP T-ALL samples by sequencing and DNA copy number analysis. ETP ALL was characterised by a high frequency of activating mutations in genes regulating cytokine receptor and Ras signalling (67% of cases; NRAS, KRAS, FLT3, IL7R, JAK3, JAK1, SH2B3 and BRAF); alterations disrupting haemopoietic development (58%; GATA3, ETV6, RUNX1, IKZF1, EP300); and inactivating mutations in histone modifying genes (48%; EZH2, EED, SUZ12, SETD2 and EP300). We also identified new targets of mutation including DNM2, ECT2L and RELN. Ten of 12 ETP ALL cases harboured chromosomal rearrangements, several of which complex and resulted in the expression of novel chimeric in-frame fusion genes disrupting haemopoietic regulators. Thus, similar to myeloid malignancies, mutations that drive proliferation, impair differentiation and disrupt histone modification are hallmarks of ETP ALL. Moreover, the global transcriptional profile of ETP ALL was similar to that of normal and myeloid leukaemia haemopoietic stem cells. These findings suggest that addition of myeloid-directed therapies might improve the poor outcome of ETP ALL.
The genetic basis of early T-cell precursor acute lymphoblastic leukaemia.
Specimen part
View SamplesDespite significant improvements in life expectancy of kidney transplant patients due to advances in surgery and immunosuppression, Chronic Allograft Nephropathy (CAN) remains a daunting problem. A complex network of cellular mechanisms in both graft and peripheral immune compartments complicates the non-invasive diagnosis of CAN, which still requires biopsy histology. This is compounded by non-immunological factors contributing to graft injury. There is a pressing need to identify and validate minimally invasive biomarkers for CAN to serve as early predictors of graft loss and as metrics for managing long-term immunosuppression.
Biomarkers for early and late stage chronic allograft nephropathy by proteogenomic profiling of peripheral blood.
No sample metadata fields
View SamplesGene expression profiling was performed on 97 cases of infant ALL from Children's Oncology Group Trial P9407. Statistical modeling of an outcome predictor revealed 3 genes highly predictive of event-free survival (EFS), beyond age and MLL status: FLT3, IRX2, and TACC2. Low FLT3 expression was found in a group of infants with excellent outcome (n = 11; 5-year EFS of 100%), whereas differential expression of IRX2 and TACC2 partitioned the remaining infants into 2 groups with significantly different survivals (5-year EFS of 16% vs 64%; P < .001). When infants with MLL-AFF1 were analyzed separately, a 7-gene classifier was developed that split them into 2 distinct groups with significantly different outcomes (5-year EFS of 20% vs 65%; P < .001). In this classifier, elevated expression of NEGR1 was associated with better EFS, whereas IRX2, EPS8, and TPD52 expression were correlated with worse outcome. This classifier also predicted EFS in an independent infant ALL cohort from the Interfant-99 trial. When evaluating expression profiles as a continuous variable relative to patient age, we further identified striking differences in profiles in infants less than or equal to 90 days of age and those more than 90 days of age. These age-related patterns suggest different mechanisms of leukemogenesis and may underlie the differential outcomes historically seen in these age groups.
Gene expression profiles predictive of outcome and age in infant acute lymphoblastic leukemia: a Children's Oncology Group study.
Sex, Age, Specimen part, Treatment, Race
View SamplesIn the present work, we have used whole genome expression profiling of peripheral blood samples from 51 patients with biopsy-proven acute kidney transplant rejection and 24 patients with excellent function and biopsy-proven normal transplant histology. The results demonstrate that there are 1738 probesets on the Affymetrix HG-U133 Plus 2.0 GeneChip representing 1472 unique genes which are differentially expressed in the peripheral blood during an acute kidney transplant rejection. By ranking these results we have identified minimal sets of 50 to 150 probesets with predictive classification accuracies for AR of greater than 90% established with several different prediction tools including DLDA and PAM. We have demonstrated that a subset of peripheral blood gene expression signatures can also diagnose four different subtypes of AR (Banff Borderline, IA, IB and IIA) and the top 100 ranked classifiers have greater than 89% predictive accuracy. Finally, we have demonstrated that there are gene signatures for early and late AR defined as less than or greater than one year post-transplant with greater than 86% predictive accuracies. We also confirmed that there are 439 time-independent gene classifiers for AR. Based on these results, we conclude that peripheral blood gene expression profiling can be used to diagnose AR at any time in the first 5 years post-transplant in the setting of acute kidney transplant dysfunction not caused by BK nephropathy, other infections, drug-induced nephrotoxicity or ureteral obstruction.
Molecular classifiers for acute kidney transplant rejection in peripheral blood by whole genome gene expression profiling.
Specimen part
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